WEATHER forecasters say parts of the Mid North Coast could be in for one of its wettest weeks in a year, bringing the threat of flooding.
After a fortnight of mostly sunny conditions, the rain clouds are set to form over the region this afternoon.
Weatherzone states this week could be one of the wettest along the East Coast since the deluges of March and July last year.
Emergency Services are taking heed of the warning, with concerns heavy rain may see roads, homes and properties inundated later in the week.
"The system is showing some similarities to the one in March 2011, which dumped flooding rain from the Hunter to the South Coast over three-or-four days," Weatherzone meteorologist Brett Dutschke said.
During that event more than 400mm of rain fell in parts of the Illawarra and South Coast and more than 200mm in parts of Sydney, the Central Coast and Hunter.
Wollongong had its heaviest rain in 20 years, gaining about 250mm in just 24 hours.
"This week's trough system should bring falls in excess of 100mm to an area from Tweed Heads to Merimbula by the weekend.
"The wettest area looks like being between Port Macquarie and Nowra and some areas are a chance to accumulate more than 300mm by the weekend, more than double the monthly average.
Showers and storms are already affecting the northeast of the state and are becoming more frequent as a low pressure trough forms over the region.
Newcastle picked up 23mm of rain overnight, its heaviest fall in two months.
"Over the coming few days this trough will deepen just offshore and slide slowly south, taking bursts of heavy rain with it. It will be fuelled by warmer-than-average seas," Mr Dutschke said.
"From Friday some drying out will occur, initially in the north and later in the south, but it won't be long before rain returns.
"There will only be about one day's break from the rain before another trough moves in from the west and brings another burst. Thankfully that rain will only be relatively brief and light. Most of it should fall over inland NSW, mainly the north, where it has been fairly dry in the last couple of months.
"Looking ahead deeper into autumn and winter, the chance of flooding rain is reduced. This is largely due to cooling waters and a neutral phase taking over from La Nina, which has only recently ended," Dutschke said